ENGLEWOOD, Colo. — He’s revived a foundering franchise with last-minute magic and put the buzz back in the Broncos. Tim Tebow’s next challenge is rebounding from the worst game of his career.

Tebow threw four interceptions in a 40-14 loss at Buffalo on Christmas Eve, two of which were returned for touchdowns in a 19-second span.

If Tebow was shaken by the first four-interception game of his life, he isn’t showing it, insisting “my confidence is just fine.”

That faith will come in handy Sunday when Tebow tries to beat the guy he couldn’t beat out in training camp — Kyle Orton, who brings the Kansas City Chiefs (6-9) to Denver with a shot at spoiling the playoff hopes of a team that shunted him aside.

The Broncos (8-7) can clinch the AFC West and their first playoff berth since 2005 with a win.

Asked if he’s confident he has the better quarterback for this matchup, Broncos coach John Fox replied: “Well, we made that decision, you know. As I always say about anything, looking forward, time will tell.”

While Tebow was in the midst of taking the NFL by storm with a six-game winning streak that included four straight fourth-quarter comebacks, the Broncos granted Orton his request for his release.

Orton was hoping to go back to Chicago, where Jay Cutler had broken his right thumb. But the Chiefs, who had lost quarterback Matt Cassel to a hand injury, had a higher waiver claim and so Orton ended up in Kansas City.

Orton dislocated a finger on his first pass attempt but rebounded to hand the Green Bay Packers their only loss with a stellar performance two weeks ago that could pay off handsomely this offseason when he becomes an unrestricted free agent for the first time.

First, he’ll get the chance to exact some revenge on the team that gave up on him.

“We knew we may have to face him down the line and we kind of took that risk,” Broncos boss John Elway said of releasing Orton on Nov. 22.

Elway said it was best for Orton to get a fresh start somewhere else after being supplanted by Tebow. Plus, it saved the Broncos $2.5 million in salary, so everybody won.

One of them won’t be a winner on Sunday afternoon.

Three weeks after the much-hyped Tim Tebow vs. Tom Brady showdown ended badly for Denver with a 41-23 defeat at the hands of the New England Patriots, the Broncos are downplaying Orton’s return to Mile High.

“I think my interpretation this week is the Denver Broncos vs. the Kansas City Chiefs,” Fox said, “and I’m sure that will be their approach as well.”

Tebow said almost exactly the same thing after his poor performance against the Bills.

“I think it’s the Denver Broncos and the Kansas City Chiefs,” he said. “That’s a great rivalry and it’ll be a great game. (I’m) excited we get to play at home in front of our fans. I think that as a player, as a quarterback, as someone who has dreamed of that his whole life, it’ll be exciting to have one game, one last game, one last opportunity to make the playoffs.”

The Broncos could lose Sunday and still make the postseason if San Diego beats Oakland. But the Broncos aren’t counting on anybody but themselves.

“In my mind, it’s much like a playoff game already,” Fox said. “For most intents and purposes, we need to win this game. And that will determine our fate.”

The Broncos are coming off their worst performance of the season, one in which they surrendered touchdowns on offense, defense and special teams, a terrible trifecta that was especially troubling coming against a team that hadn’t won since October and was long ago eliminated from the playoff picture.

They made the Bills look like the Patriots.

Cornerback Champ Bailey said he’s stumped as to why the Broncos keep finding themselves in a fourth-quarter fix: “I just know at some point throughout the second and third quarter we find a way to make it hard for ourselves.”

After overcoming deficits all year, the Broncos haven’t been able to do it the last two weeks.

Elvis Dumervil lamented the lack of big defensive plays since Wesley Woodyard forced a fumble in overtime that led to a win over Chicago on Dec. 11. He said the solution was threefold: “No turnovers, stopping the run and getting after the quarterback. That’s the way you win.”

In their last two games, the Broncos are minus-7 in takeaways, have just three sacks and have yielded 301 yards rushing. That’s the way you lose.

None of those quarterback takedowns have come from rookie linebacker Von Miller, who is stuck on 11¬Ω sacks, three shy of Jevon Kearse’s NFL rookie record set in 1999.

“It’s that big cast on his thumb,” Fox said. “It’s hard to play this game with both hands let alone just one.”

Miller tore ligaments in his right thumb, an injury that required surgery and sidelined him for one game.

“It’s definitely a factor,” Fox said. “A different type of cast isn’t going to let him use his hand any differently because we still have to immobilize the thumb. We’ll make do. He’ll get better and so will we.”

The Broncos, however, might have to face Orton with a makeshift secondary. Safety Brian Dawkins left last week’s game with a recurring neck injury that could spell the end to his stellar 16-year NFL career that includes eight Pro Bowls.

Fellow starting safety Quinton Carter pulled a hamstring and nickel back Chris Harris hurt his neck, too. That means the starting safeties might be Raheem Moore and David Bruton, which could affect defensive coordinator Dennis Allen’s aggressive approach against Orton, who went 6-21 with the Broncos after winning his first six games with them in 2009.

The Chiefs were eliminated from playoff contention last weekend, so they’re strictly playing the spoiler role, just as they were two years ago when they came into Denver and thumped the Broncos 44-24.

“I’m always fired up about a game regardless of who it is,” Broncos running back Willis McGahee said. “This is a game we need and must take, a must-take game. We need to go into that game and play lights-out football.”

Or the lights could go out on another Broncos season without a trip to the playoffs.

Notes: Fox said he hasn’t decided whether to keep the Chiefs-Raiders score and stats off the stadium’s scoreboards Sunday: “I would hope our focus is all on the field against Kansas City,” he said.